Applicators and methods for intraoperative treatment of proliferative diseases of the breast

ABSTRACT

A device for administering brachytherapy to a patient includes a vessel that may be in the form of a hollow cylindrical cup, for fleshing into and substantially filling the open-ended cavity. The vessel has a closed outer end, which may be a removable cover, and a source guide penetrates the closed outer end so as to extend deep into the vessel, to receive a radiation source in the source guide. A manipulator can be connected to the radiation source, and also to the source guide, for allowing several different types of manipulation of the source orientation and position within the vessel during the brachytherapy procedure.

BACKGROUND OF THE INVENTION

This invention relates to radiation therapy of proliferative disease asrequired adjuvant care following surgical resection of tumors or otherpathological conditions. More particularly, it pertains to theintraoperative application of therapeutic radiation emitted fromradiation sources positioned within the resection cavity created bysurgical resection. Discussion herein is largely directed toradiotherapy following at least partial resection of breast tumors, butit is to be understood that the apparatus and methods may be applied todifferent anatomical sites.

It has been demonstrated in many areas of surgical oncology thatadjuvant radiation treatment following tumor resection reduces thelikelihood of recurrence of cancer or other proliferative disease. Thelikelihood of infiltrative disease decreases with distance from aprimary site in a tissue with confirmed disease. It has also been shownthat brachytherapy delivered from within the resection cavity is aseffective as external beam therapy, reduces exposure of normal tissue toinadvertent radiation exposure, and furthermore, that quality of life issuperior after brachytherapy compared to that following external beamtherapy. It is therefore desirable that brachytherapy orbrachytherapy-like techniques be made available to as great a populationof patients as possible.

Many radiotherapists prefer to deliver radiotherapy in fractions spacedin time (over a period of several days or even weeks) usingintracavitary brachytherapy techniques to take advantage of the factthat normal cells recover from radiation exposure in a shorter period oftime than diseased cells. Other radiotherapists have foundintraoperative radiation therapy (IORT, radiotherapy delivered duringthe same operative procedure as the tumor resection) to be equally ifnot more effective in many circumstances, and may offer the opportunityfor simultaneous reconstructive surgery. This invention pertains toIORT, or delivery of other single-treatment radiotherapy wherein acomplete treatment or prescription is delivered from the resectioncavity in one dose during a conventional open surgical procedure. It hasalso been demonstrated that radiation intensity diminishes with distancefrom the radiation source. Radiotherapists fairly universally havetherefore found that it is generally desirable to spatially separate theradiation source from the tissues being treated. This reduces thelikelihood of exposing normal tissue to harmful levels of radiation,particularly that tissue nearest the radiation source, while stilldelivering the prescribed radiation to the prescribed depth. In asituation where the resection cavity is substantially centered on thesite of the tumor, the prescription depth is the depth in tissue outsidethe resection cavity where the likelihood of undiagnosed disease ishighest and where adjuvant radiation treatment is warranted. The targettissue is the tissue to which this prophylactic radiotherapy isdirected, generally lying outside the resection cavity, but within thebounds of the prescription depth. Where the cavity (and hence theresected tissue specimen) is eccentric about the tumor location, thatportion of the cavity farthest from the tumor may require less radiationprescription depth than tissues near the resected tumor location.

To create this spatial separation in traditional intracavitarybrachytherapy, an applicator, usually comprising a balloon, ispositioned and inflated within the resection cavity. For the samereasons as above, it is also desirable to create spatial separationpreparatory to IORT treatment within an open surgical cavity. Atpresent, however, there are no applicators, analogous to the balloonapplicators described above, for use with IORT methods in open surgicalfields. A purpose of this invention is to fill that need.

Traditional brachytherapy sources are isotopic seeds, often of iridium192 positioned on wires, which are manipulated within applicator sourceguides and balloons to deliver the prescribed treatment to the targettissue surrounding the balloon and resection cavity. Emissions fromiridium and other common medical isotopes usually have high-energycomponents which can penetrate deeply into tissue. They also emitcontinuously, and thus can only be used in special, heavily-shieldedrooms. In addition, concerns for the safety of personnel requireisolation of the patient during treatment, shielded storage at all othertimes, and automated handling between the storage chamber and theapplicator when in the patient. In total, the capital expense requiredfor such facilities dictates that treatment centers be located in urbanareas so as to serve sizeable patient populations. This can result inunder serving rural patients who cannot repeatedly travel to urbantreatment centers for a course of prolonged radiation treatment.Furthermore, the need for patient isolation is inconvenient fortherapists, not to mention daunting for the patients under treatment.With such brachytherapy, it is clear that any improvements to the totalduration of treatment, cost, source handling and shielding difficulties,patient fear factors and inconvenience would be welcome.

Recently, miniature electronic x-ray tubes have provided a preferablealternative to use of isotopes. Such tubes do not emit continuously,they only emit when powered in a manner causing emission and they can beturned on and off, or if desired, modulated such that their penetrationdepth can be controlled (by control of acceleration voltage) and theirdose intensity can be controlled (by filament current) as well. Onereference describing the principles and construction of such tubes isAtoms, Radiation and Radiation Protection, Second Edition, John E.Turner, Ph.D., CHP, 1995, John Wiley & Sons, Section 2.10. Electronicbrachytherapy sources generally require cooling and are usuallycontained in a fixed position within a catheter designed for thepurpose, but otherwise are more versatile and convenient to use thanisotopes, and can be engineered to accommodate a wide variety ofdosimetric prescription detail. In addition miniature x-ray tubes can bedesigned to emit substantially isotropically, or directed to emit onlythrough a predetermined solid angle, permitting more detailed treatmentplans. Isotope radiation cannot be controlled in this manner.Furthermore, the x-ray energy spectrum in ranges suitable forbrachytherapy or IORT eliminates the need for heavily shieldedstructures, or “bunkers”, and also permits the therapist to be in theroom with the patient during therapy. Therapy can proceed in almost anymedical facility, urban, rural or even mobile, and therefore, withminiature x-ray tubes, a greater population of patients can be treated,and the costs of therapy are greatly reduced. It is clear thatelectronic brachytherapy sources have already contributed significantlyto making such therapy more readily available and cost effective thanother methods. Treatment duration can still be improved, however, andIORT is a procedure directed to this end.

Tumor resection is usually carried out by open surgical technique wherethe surgeon proceeds directly through skin and tissue overlying thetumor, or at the surgeon's discretion, from a nearby point which mayprovide more pleasing cosmesis. The incision must accommodate tumorresection including excision of additional tissue around the tumor, themargins of which are believed to be disease free. Often, efforts aremade to provide markers which help orient the tissue with respect to thecavity from which it was excised, and which provide a basis thepathologist and surgeon can use to communicate with respect to theprecise location of the tumor within the specimen (thus the cavity)and/or the location of further disease at the margins. Once analyzed,and if necessary, further tissue is removed until the margins are“clear”, or free of apparent disease. In some modern institutions, thispathologic assessment is performed while the patient is stillanaesthetized and on the operating table. Once the margins aredetermined to be free of disease, if IORT is the radiotherapy of choice,it is then administered.

Because the extent of the disease is uncertain at the outset of surgery,the incremental nature of the resection procedure in response topathological findings may result in a cavity, the boundaries of whichare eccentric with respect to tumor, and some margins which arerelatively farther removed from the original tumor than others, and thusless likely to be infiltrated with disease. In such a circumstance, theprescription dose can be specified for delivery to an imaginary surfacedefined in relation the tumor location without reference to the cavityboundaries. It is an object of this invention to accommodate sucheccentricity so that tissues lying farthest from the tumor receive alower dose than those lying near the tumor site, and to facilitatepreparation of such a treatment plan.

Other objectives of the invention will become apparent from thefollowing summary, drawings and description.

SUMMARY OF THE INVENTION

This invention is intended particularly for the breast and comprises arigid cup of predetermined shape, the sides of which are transparent toradiation and visible light, and the bottom of which is optionallyattenuating in order to shield the underlying tissues and organs fromharmful radiation. The cup is placed into the cavity, bottom first, andadvanced until it reaches the bottom of the cavity. The cup isconfigured so as to substantially fill and shape the cavity. If desired,the cup can be sutured near its base to secure it to the bottom of thecavity. After being so placed, the conformance of the cavity tissue tothe cup can be visually ascertained, and if necessary adjustedappropriately to eliminate voids or pockets of air or seroma.Alternatively, the surrounding tissue can be urged into conformance withthe sides of the cup and held in place by conventional tapes and/orsutures, by selecting a differently shaped rigid cup, or by othermethods including provision of a matrix on the outside of the cup forapplication of suction to draw breast tissue into conformance with thecup and so retain it during radiotherapy.

The invention further comprises a lid to cover the cup and a connectionwith a gasket or other conventional features proximate to the cup lip tocreate a fluid tight seal between the two elements. Near or at theperiphery of the lid is a radiation attenuating skirt extending distallyinto the cup or just outside the cup (with securement threads forengaging the cup) to shield the skin and near-skin tissue gatheredaround the cup from radiation. If desired, the entire lid (or lidassembly if comprised of multiple elements) can be attenuating toprotect those nearby during radiotherapy delivery. Extending through thelid is a tubular source guide which is radiation transparent and reachessufficiently into the cup such that a radiation source can deliver astherapeutic dose. In one embodiment, the source can be manipulatedwithin the guide (such positioning herein referred to as along the “Z”axis of the applicator or cavity) to effectively deliver the prescribedradiation. The distal end of the source guide is closed. Proximally, theguide extends outward of the lid to an open end where a source andcatheter can be inserted. If source manipulation is desired, theproximal end of the source guide further comprises a flexible extensionwhich can be secured to the source manipulator located outside thepatient in order to provide a fixed reference distance between theoutside manipulation apparatus to the patient and applicator. Such aflexible connection can accommodate patient motion, for example motiondue to respiration, without introducing error in source positioning.

In simplest form, the cup is circular and the source guide is normal tothe lid and located centrally to position the source equidistant fromthe sides of the cup in order for a substantially isotropic source toproduce a laterally uniform isodose pattern. Other lid shapes and sourceguide positioning can be used to accommodate irregular cavity shapesand/or non-uniform prescription situations, and even source guidepositions which are varied during the radiotherapy procedure. If thesource position is to be varied laterally in the X and/or Y directions,the surface of the lid can comprise a membrane to which the source guideis secured and sealed, and which can accommodate the desired changes inposition, X/Y or angular. Conventional servo-systems can provide suchmanipulation in response to computer commands, and with sourcepositioning within the source guide along the Z axis, can position thesource at any location within the cup.

Delivery of radiotherapy using such a system is preceded by a treatmentplanning procedure in which the anatomy and applicator apparatus may beimaged using conventional methods, usually either x-ray or CT, but sincethe cup is transparent and its shape is known, direct visualization maybe adequate to check for tissue conformance to the cup such that thetissue can be gathered more effectively around the cup, and to identifythe presence of pockets of air or seroma between the cup and tissue.Once the geometrical relationships are confirmed, the desired therapycan be planned and the source position(s) and/or manipulationdetermined. Ultimately, control parameters for the apparatus areprogrammed to produce the plan for use during treatment. Prior totreatment, and if desired before imaging and planning, the volume withinthe cup and lid is filled with an attenuating medium, preferably saline,and air from within the volume is vented if necessary. Next, a radiationshield or shields, perhaps with a hole to accommodate exit of the sourceguide, are draped on the patient around the applicator apparatus asnecessary to protect those nearby during treatment. (See U.S. patentapplication Ser. No. 11/323,331.) The source is then inserted into theapplicator, connected to the positioning control apparatus, if any, andtreatment initiated. After delivery of the prescription, the source andother apparatus are removed. If any intraoperative reconstruction isindicated, it is performed, and the cavity is then closed surgically ina conventional manner.

If desired, radiation sensors can be mounted on the skin or on theapplicator apparatus to assist in dose determination during thetreatment planning process, or to monitor treatment to plan and/or warnof overdose during radiotherapy.

Although the description herein assumes x-ray therapy from miniaturex-ray tubes, the apparatus may also be used with isotopes to similareffect. From the embodiments described herein, other features, apparatusconfigurations and procedures will be apparent to those of skill in theart. Such improvements are to be considered within the scope of thisinvention.

DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts in cross section a simple cup embodiment of the inventionpositioned within the breast of a patient and sutured therein usingsuture tabs provided for this purpose.

FIG. 2 shows schematically in perspective a brachytherapy treatmentsystem including an applicator apparatus of the invention.

FIG. 3 shows in cross section breast tissues gathered around theapplicator with the cup, a lid and gasket assembled and a flexibleextension of the source guide leading to an outside manipulator.

FIG. 4 is a perspective view showing a source catheter positioned in themanipulator and flexible source guide extension in preparation forcontrolled delivery of radiotherapy.

FIG. 5 is a perspective view showing schematically an applicator lidwith provision for X/Y manipulation of the source guide, and controlwires for connection to actuators for X/Y manipulation.

FIG. 6 shows schematically in cross section, detail of the applicator ofFIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows in section view, a preferred brachytherapy applicator cup10 positioned in an open surgical cavity 12 left in the breast 14 of apatient following (at least partial) tumor resection. The cup preferablyis substantially rigid, of a predetermined shape (in this examplecircular), and preferably substantially transparent to x-rays and tovisible light, or at least partially transparent to x-rays. It may, forexample, be molded from engineering plastic, preferably with a specificgravity near unity to simplify treatment planning. Suitable materialswould include polycarbonate, polyphenolene ether (Noryl, from GEPlastics, is an example) and polyethersulfone (Radel, from SolvayAdvanced Polymers is another example). The shape can be generallycircular-cylindrical, or other shapes.

If the tissues at the bottom of the cavity are susceptible to radiationdamage and are to be protected, the material of the bottom portion 16 ofthe cup may further comprise the addition of attenuating fillers (seecross-hatching at bottom portion 16) to shield such tissues, oralternatively, an attenuating coating can be applied to the bottom ofthe cup. Barium compounds or metallic particulates may be used forfilling purposes, but the separate filled and unfilled portions of thecup may require separate molding and subsequent joining together, as bybonding for example.

The distal bottom of the cup is positioned at the bottom of the cavityand if desired, secured with conventional sutures 18 to maintain cuporientation within the surgically created cavity. An optional flange ortabs 20 may be provided for suturing purposes. Alternatively, a base(not shown) to be located under the cup may be sutured similarly in thebottom of the cavity. The cup bottom can be retained to the base by asuitable releasable attachment means. For example, the base may comprisehalf of a conventional hook and loop fastener (VELCRO), to which amating fastener portion secured to the outside of the bottom of the cup,such as by bonding, is used to anchor the cup in the cavity. In anothervariation where a base is used, the bottom of the cup could comprisehalf of either a screw-thread or snap-on fastener and be attached to thebase by mating screw thread or snap-on fixation. It is also possible thecup could be inverted and its open mouth screwed onto such a threadedbase, with apparatus described below emerging from the upper side, whichwould be the cup bottom. It is also possible to use a vessel which ispermanently closed but with a top opening to accommodate the radiationapparatus described below; for small resection cavities the vessel couldcomprise a solid mass of plastic material with a guide channel extendinginto it from the outer side. The term vessel is intended to include sucha configuration of an applicator.

In instances where the tissues under the cup are to be shielded fromradiation, rather than filling the cup bottom with attenuating material,one or both portions of the hook and loop fastener or the base suturedto the bottom of the cavity may further comprise a shielding layer, forexample a layer of metallic foil or filled polymer.

A range of applicator cup sizes and shapes may be offered as standard,from which the surgeon or radiation oncologist may choose to fit thepatient's resection cavity, or in the alternative, and where there issufficient time and information available, a cup can be fabricated whichaddresses a particular patient's requirement. Proximate to the cup's lipare screw threads 22 to mate with the lid (not shown in this drawing)presuming the cup is circular as shown. If the cup is not of circularcross-section, conventional over-center or snap-on fasteners can be usedwith features molded into the cup and lid for the purpose, which can beas in plastic food storage containers.

FIG. 2 shows the principal elements of the treatment systemschematically. The elements comprise a treatment planning computer 24used to create an optimized treatment plan based on the doseprescription and on cup shape, and if conventional imaging is performedprior to planning, also on other relevant information from the imagingdata. Imaging information, particularly if by CT methods, may alsoreveal tissue conformance to the cup 10 and location of anatomy whichmay require shielding or other accommodation. The computer 24 may, inone form of the system, then provide the treatment plan to thecontroller (not shown) which manages control of the source output,source position spatially and the timing of exposure from radiationemissions in order to deliver the prescribed treatment. Parts of thecomputer 24, controller and other elements of the treatment systemcommunicate by conventional wiring 25, and ultimately source positioningis controlled through a mechanical manipulator 26 which positions thesource 28 as needed within the cup and therefore within the resectioncavity. The computer and controller can be a single component, and theterm “controller” as used in the claims and sometimes herein is intendedto refer to either implementation.

With the preferred miniature x-ray tube sources, the source 28 isusually contained and carried within a source catheter 32 to which thesource is rigidly affixed. The catheter 32 is shown positioned in thecollet 34 on the sled 36 of the controlled portion of the manipulator.Where required, conventional fluid cooling apparatus (not shown) isprovided, and cooling fluid is supplied at the manipulator apparatusfrom whence it flows to the x-ray source itself within the catheter.

The applicator 38 of the system comprises a tubular source guide 40which is preferably rigid and transparent to radiation. The distal end42 of the source guide is closed. Proximally, the source guide 40 isaffixed to the lid 44 of the cup 10. The source guide distal end 42 isthus positioned in the cup 10 when the lid is in place. The proximal end45 of the source guide connects to a flexible extension 46 of the sourceguide that preferably is anchored to a stationary portion 48 of themanipulator 26. This establishes a constant source guide lumen lengthfrom the manipulator to the source guide distal end 42 positioned withinthe applicator cup such that the controller can precisely controlmanipulation of the source 28 within the source guide 40, in the mannerof a control cable. The cup 10 and the lid 44 of the applicator 38 areshown assembled as if positioned in the patient's breast or the anatomy(not shown). The source guide portion within the cup is preferablystraight, but need not be if necessary to accommodate a non-uniformprescription.

In explanation, control cables of the sort described above with respectto source manipulation are sometimes called Bowden cables, and comprisea flexible tubular outer sheath of fixed length, the ends of which arefixed to two different structures whose relative position need not beeither constant or predetermined. Within the control cable sheath is awire (or in this case, source catheter 32) which can be translatedaxially. Pushing or pulling a given amount on one end of the wireresults in a substantially identical displacement at the other end ofthe wire. An automobile throttle cable is a common example of such acontrol cable.

In FIG. 3 the applicator 38 is shown submerged in a cavity of tissuesuch as a breast 14. The tissues of the breast 14 have been gatheredaround the cup 10 and lid 44 and are held in place by conventional tape,sutures, or other conventional methods familiar to surgical practice.The lid 44 of the cup 10 is shown assembled to the cup with a gasket 49,for example of silicone, positioned between cup and lid to seal thevolume within. The lid has the central source guide 40 preferablyaffixed to the lid by conventional methods, an example of which is acollet 50, and extending into the cup, with the proximal end 45 securedto the flexible extension 46 by a conventional clamp 49. If necessary toprotect the patient's skin and near-skin tissues from overdose whichcould result in adverse cosmesis, the lid can further comprise a skirt51 of a shielding material extending coaxially inside the lip of the cupto a depth sufficient to protect the skin and near-skin tissues asshown. Alternatively, the cap's threaded skirt 51 a could includeshielding material. A flexible drape 52 according to the teachings ofU.S. patent application Ser. No. 11/323,331 is shown draping the breast14 to protect attending personnel. The lid 44 may also be of a shieldingmaterial in order to provide radiation exposure protection totherapeutic personnel, either as a single molding as shown, oralternatively, the lid can comprise an assembly of parts. Depending onthe attenuating properties of the lid elements, which include thethreaded skirt 51 a, the attenuating skirt 51 may be redundant and canbe eliminated. Also shown on the top of the lid is a vent 56 to permitair to escape from the interior volume of the applicator as the cup isfilled with attenuating medium through an inlet port 58.

FIG. 4 shows in greater detail the manipulator apparatus 26. Theproximal end of the source guide flexible extension 46 is mounted to thestationary portion 48 of the manipulator. The source catheter 32 isshown positioned within the collet 34 and extending into the sourceguide extension 46. The source catheter 32 and hence the source (notshown) are controlled spatially by servomotors 61 of the manipulator inresponse to commands from the controller or computer. The manipulatorshown schematically in FIG. 4 can accommodate both translation of thesource axially within the source guide as well as rotation relative tothe source guide, the latter for use with x-ray tubes emitting onlythrough a solid angle (directional) rather than isotropically. Ininstances where isotropic source are used, only axial manipulation isrequired and the rotational capability of the manipulator 26 as shownmay be eliminated. Furthermore, if it is desired to translate the sourcewithin the source catheter, a second manipulator (not shown) similar tothe manipulator 26 may be added to operate in tandem with themanipulator 26 and provide independent control for both source andcatheter.

FIG. 5 depicts schematically a lid embodiment and system where the topof the lid 62 comprises a membrane 64, for example of silicone, to sealthe volume within the cup 10 while the source guide (not shown) istranslated in the X and/or Y directions by a servomotor positioningapparatus 66 mounted on the stationary portion 48 of the manipulatorapparatus. Applicator guide rails 68X, integral parts of the lid 62,guide a X sled 70X in the X direction, while the edges of the sled 70Xguide a sled 70Y in the Y direction. Both sleds are controlled byservomotors 72X and 72Y respectively, acting through control cables 74Xand 74Y of the sort described above. The servomotors 72X and 72Y areresponsive to commands from the central controller. Collectively, thisapparatus serves to keep the source guide parallel to the axis of thecup during X/Y translation. In principle such X/Y apparatus could bemounted entirely on the lid of the applicator, but given any substantialbulk or weight for the positioning apparatus, it is preferable to mountthe positioning servomotors remotely, for example on the stationaryportion 48 of the manipulator apparatus as shown.

In this embodiment, the proximal end of each of the control cable 74Xand 74Y sheaths is affixed to the stationary portion 48 of themanipulator apparatus, as is the proximal end of the source guideflexible extension 46. The source catheter 32 is mounted in the collet34 and leads into the flexible source guide extension 46. The distal endof the sheath of the cable 74X is fastened to a mounting tab 76 on thelid 62. The distal end of the sheath of cable 74Y is mounted on a tab78, an integral part of the sled 70X. The proximal ends of the innerwires of the two cables are controlled by the axial servomotors 72X and72Y. The distal end of the inner wire of the cable 74X is connected to atab (not shown) proximate the central slot 80X of the sled 70X. Thedistal end of the inner wire of the cable 74Y connects to a tab 82 onthe sled 70Y (see FIG. 6 for detail). With this arrangement, andtogether with manipulation of the source catheter 32, the source may bepositioned anywhere within the cup 10 by X,Y,Z coordinates which fallwithin the mechanical limits of the apparatus.

Although the source guide manipulation above is limited to X and Ytranslation, other manipulation strategies can be used, for example bypivoting an arm mounting the source guide 40, where the radius of thesource guide from the pivot and the pivot angle are controlled. It isalso possible to vary the angle of the source guide axis relative to thecup axis. Servomotors can be used to control the positions of all thesevariations in keeping with the degrees of freedom of motion provided bythe apparatus. Still other control schemes will be readily apparent tothose of skill in the art. If desired, closed loop feedback control foreach degree of freedom employed can be provided easily, for example byuse of linear variable differential transformer (LVDT) sensors, theoutput of which can be used to verify position with precision. Sensoroutputs can also be used to verify treatment to plan. Such methods areknown to those of skill in the art.

FIG. 6 is a cross section detail through the axis of the source guide40, looking in the X direction. The membrane 64 is shown clamped ontothe source guide 40 by a clamp 84. The mounting of the sled 70X on therails 68X is seen in FIG. 6.

Various embodiments employing combinations of features described aboveare useful for IORT. The simplest case is a source guide positioned in afixed position within a cup of circular cross-section, and asubstantially isotropic source in a fixed position or translated withinthe source guide. Special circumstances can be accommodated with otherembodiments. For example, if the resection cavity from tumor removalresults in a cavity which is not centered on the tumor location, asdiscussed above, perhaps as a result of successive adverse pathologyfindings or for any other reason, the prescription can be centered onthe tumor location by use of a source guide passing through the tumorlocation rather than being centered within the cavity. The cup and lidcan still be chosen to fill the cavity, be it round or oval in crosssection, or of another shape. Since the likelihood of diseaseinfiltration into apparently normal tissue decreases with distance fromthe tumor, when using this approach, the farthest tissues from the tumorwill receive a lighter dose. To the extent that a portion of the targettissue limits fall within the cup, the tissues beyond may receive verylittle dose, while the tissues nearer the tumor will receive the fullprescription. With the embodiment described in FIG. 5, the isodosepattern circumscribing the prescription may be sculpted beyond shapesavailable from a fixed source position or from a linear source guidewithin which the source is translated.

Although described particularly in relation to breast radiation, theapplicator and accompanying control apparatus can be used at othertissue locations wherein a resection cavity or other cavity is open atthe skin.

The embodiments described above will suggest to those of skill in theart, other combinations of features which, when combined, will result infurther embodiments. These embodiments are to be considered within thescope of the invention.

1. A device for administering brachytherapy to the tissue of a livingpatient, comprising: a cup of a material at least partially transparentto x-ray radiation, a cover for the cup, a source guide for receiving anx-ray source attached to and penetrating through the cover for the cup,and a catheter carrying an x-ray source slidable within the source guidein the cup, whereby the cup can be positioned in an open resectioncavity with the tissue closely up against a bottom and sides of the cup,and with the cover on the cup and the source guide within the cup, thecatheter can be manipulated axially within the source guide in the cupas a brachytherapy treatment of tissues surrounding the cup progresses,and a manipulator for moving the source guide in at least one of X and Ydirections of translation within the cup, the X and Y directions beingparallel to the cover of the cup, so that the radiation source can bemoved to different positions within the cup during the brachytherapytreatment.
 2. The brachytherapy applicator cup of claim 1, wherein thecup is essentially circular-cylindrical.
 3. The brachytherapy applicatorcup of claim 2, wherein the cover is securable to the outer end of thecup using screw threads.
 4. The brachytherapy applicator cup of claim 1,including a manipulator connected to a proximal end of the catheter andcapable of manipulating the catheter and the x-ray source at least in anaxial direction within the source guide when the source guide iscontained within the cup.
 5. The brachytherapy applicator of claim 4,wherein the manipulator includes provision for rotation of the catheterwith the radiation source, as well as axial translation of the catheter.6. The brachytherapy applicator cup of claim 1, wherein the cup has aprovision for suture near its bottom for suturing the cup to tissue atthe bottom of the resection cavity.
 7. The brachytherapy applicator cupof claim 1, wherein the cup is substantially transparent to both x-rayradiation and visible light.
 8. The brachytherapy applicator cup ofclaim 1, further including a controller connected to the manipulator andcapable of manipulating the catheter and x-ray radiation source inaccordance with a treatment plan stored in the controller.
 9. Thebrachytherapy applicator cup of claim 1, wherein the cover includes askirt, with the skirt including an attenuating material to protect theskin against radiation.
 10. A device for administering brachytherapy tothe tissue of a living patient, comprising: a cup of a material at leastpartially transparent to x-ray radiation, a cover for the cup, a sourceguide for receiving an x-ray source attached to and penetrating throughthe cover for the cup, a catheter carrying an x-ray source slidablewithin the source guide in the cup, and a manipulator connected to aproximal end of the catheter and capable of manipulating the catheterand the x-ray source at least in an axial direction within the sourceguide when the source guide is contained within the cup, wherein themanipulator includes provision for rotation of the catheter with theradiation source, as well as axial translation of the catheter, wherebythe cup can be positioned in an open resection cavity with the tissueclosely up against a bottom and sides of the cup, and with the cover onthe cup and the source guide within the cup, the catheter can bemanipulated axially within the source guide in the cup as abrachytherapy treatment of tissues surrounding the cup progresses, andwherein the manipulator further includes provision for moving the sourceguide in X and Y directions of translation within the cup, the X and Ydirections being parallel to the cover of the cup, so that the radiationsource can be moved to essentially any position within the cup duringthe brachytherapy treatment.
 11. A device for administeringbrachytherapy to the tissue of a living patient, comprising: a cup of amaterial at least partially transparent to x-ray radiation, a cover forthe cup, a source guide for receiving an x-ray source attached to andpenetrating through the cover for the cup, a catheter carrying an x-raysource slidable within the source guide in the cup, and a manipulatorconnected to a proximal end of the catheter and capable of manipulatingthe catheter and the x-ray source at least in an axial direction withinthe source guide when the source guide is contained within the cup,whereby the cup can be positioned in an open resection cavity with thetissue closely up against a bottom and sides of the cup, and with thecover on the cup and the source guide within the cup, the catheter canbe manipulated axially within the source guide in the cup as abrachytherapy treatment of tissues surrounding the cup progresses, andwherein the manipulator further includes provision for moving the sourceguide in X and Y directions of translation within the cup, the X and Ydirections being parallel to the cover of the cup, so that the radiationsource can be moved to essentially any position within the cup duringthe brachytherapy treatment.
 12. The brachytherapy applicator cup ofclaim 11, wherein the cover includes a flexible membrane secured to thesource guide and flexible so as to allow movement of the source guide inX and Y directions, while providing a closure seal for the cup.
 13. Adevice for administering brachytherapy to the tissue of a livingpatient, comprising: a vessel formed of a material at least partiallytransparent to x-ray radiation, with a substantially closed outer end onthe vessel, a source guide extending into the vessel from the outer end,for receiving an x-ray source, and a catheter carrying an x-ray sourceand positioned within the source guide in the vessel, whereby the vesselcan be positioned in an open resection cavity with the tissue closely upagainst a bottom and sides of the vessel, and with the x-ray sourcepositioned within the source guide in the vessel, brachytherapytreatment can be administered to tissues surrounding the vessel, and amanipulator for moving the source guide in at least one of X and Ydirections of translation within the cup, the X and Y directions beingparallel to the cover of the cup, so that the radiation source can bemoved to different positions within the cup during the brachytherapytreatment.
 14. The device of claim 13, wherein the vessel comprises ahollow cup with a removable cover serving as the outer end, the sourceguide being attached to and penetrating through the cover.
 15. A methodfor brachytherapy treatment of an open resection cavity in the tissue ofa living patient, comprising: following resection of a tumor in a waythat leaves an open resection cavity, placing a treatment cup into theresection cavity, assuring that margin tissue around the resectioncavity, including the skin, is essentially in contact with the outsidesurface of the cup all around the cup, placing in the cup, through anessentially closed proximal outer end of the cup, a source guide securedto and penetrating through the outer end so as to extend a distal end ofthe guide essentially to the bottom of the cup, inserting into thesource guide, through a proximal end of the source guide, a cathetercarrying an x-ray source such that the x-ray source extends into thecup, using the x-ray source to irradiate the tissues surrounding thecup, and manipulating the catheter from a proximal part of the catheter,wherein the manipulating step further includes movement of the sourceguide in at least one of X and Y directions during treatment relative tothe cup, wherein X and Y directions are substantially parallel to a topsurface of the cup.
 16. The method of claim 15, wherein the cup's wallsand bottom are substantially transparent to x-ray radiation.
 17. Themethod of claim 15, further including, following the step of insertingthe catheter, moving the catheter so as to move the radiation sourceaxially within the source guide while irradiating the tissuessurrounding the cup.
 18. The method of claim 17, further includingmanipulating the catheter using a mechanical manipulator connected to aproximal part of the catheter.
 19. The method of claim 18, wherein themanipulating step is accomplished using a mechanical manipulating deviceconnected to a proximal part of the catheter, connected to a computerprogrammed with a treatment plan, such that the manipulator moves thex-ray source in accordance with the treatment plan.
 20. The method ofclaim 19, wherein the source is directional, and including rotating thecatheter and source during the irradiation treatment, under control ofthe manipulator and the computer.
 21. The method of claim 17, whereinthe x-ray source is directional, and including the step of rotating thesource while moving the source within the source guide and the cup, toirradiate surrounding tissues in accordance with a treatment plan. 22.The method of claim 15, further including securing the cup to tissue inthe resection cavity to hold the cup in position during treatment. 23.The method of claim 15, wherein the closed outer end of the cupcomprises a removable cover.
 24. The method of claim 23, wherein thecover includes a skirt, with the skirt including an attenuating materialto protect the skin against radiation.
 25. A method for brachytherapytreatment of an open resection cavity in the tissue of a living patient,comprising: following resection of a tumor in a way that leaves an openresection cavity, placing a treatment cup into the resection cavity,assuring that margin tissue around the resection cavity, including theskin, is essentially in contact with the outside surface of the cup allaround the cup, placing in the cup, through an essentially closedproximal outer end of the cup, a source guide secured to and penetratingthrough the outer end so as to extend a distal end of the guideessentially to the bottom of the cup, inserting into the source guide,through a proximal end of the source guide, a catheter carrying an x-raysource such that the x-ray source extends into the cup, using the x-raysource to irradiate the tissues surrounding the cup, further including,following the step of inserting the catheter, moving the catheter so asto move the radiation source axially within the source guide whileirradiating the tissues surrounding the cup, further includingmanipulating the catheter using a mechanical manipulator connected to aproximal part of the catheter, wherein the manipulating step isaccomplished using a mechanical manipulating device connected to aproximal part of the catheter, connected to a computer programmed with atreatment plan, such that the manipulator moves the x-ray source inaccordance with the treatment plan, and wherein the manipulating stepfurther includes movement of the source guide in X and Y directionsduring treatment relative to the cup, wherein X and Y directions aresubstantially parallel to the cover on the cup.